Locomotive combustion control



April 1951 F. D. MOSHER 2,547,339

LOCOMOTIVE COMBUSTION CONTROL Filed Nov. 6, 1947 5 Sheets-Sheet 1 I N V EN T 0R. Fez-'0 .D- Mas/1'56 April 3, 1951 F. D. MOSHER LOCOMOTIVE COMBUSTION CONTROL 5 Sheets-Sheet 2 Filed Nov. 6, 1947 INVENTOR.

@500. Mai/1E? A ril 3, 1951 F, D M SH 2,547,339

LOCOMOTIVE COMBUSTION CONTROL Filed Nov. 6, 1947 5 Sheets-Sheet 5 I N V EN TOR. 5 50 2, Mas/1E2 BY W15 %/M April 3, 1951 F. D. MOSHER LOCOMOTIVE COMBUSTION CONTROL 5 Sheets-Sheet 4 Filed Nov. 6, 1947 WIIIJIIIIIII INVENTOR. Fee-a B M04715? HrraeA EY April 3, 1951 F. D. MOSHER LOCOMOTIVE COMBUSTION CONTROL 5 Sheets-Sheet 5 Filed Nov. 6, 1947 kunmQ ubpn'theboiler'tohsfarh;

Patented Apr. 3, 1951 UNITED STATES 225473339;

LO'CDMGTIVE GOMBUS T'IQKT obNT-Rok Fad ng-115 M fiiie-Pa assign'olfjo 'iii'egtg 'ajrd Stoke; Schwinn-Incorporated;.-a; corporate" atioii-Nwemter s, 1947, Serial No. 784,365.

(mettle-is;

6 'Claims:

This invention reiates:=to'tco'al fired-steam-loco= motivesyand1 more-- particularly; to an; improved combustionzcontrolsystem for regulating theiuel and air supply to; the 1 locomotive fireboxe Among; the broader-objects of my invention are the provision of; an: improved "coal firedlocomotive havinggreater availability, reliabilit and: lower overallloperating costs :than'pr-ior:coal fired-steam locomotives; and in whichsfiringand=oare ofthe firerrequires a minimum a ofattention by the en"- ginewcrew;thereby-permitting: the'crew more-time fore other. duties; andin which, greater combus tioneflicie'ncy is realized; thereby? contributing to reduction in smoke and decreased fuelcosts; andin which longer stand=by: time is -per-mitteci without manual attention to; the firet- V In v attaining thesezobjeets it is -impor-tantthat the -coal and-the air 1 for combustion: be supplied irf the-proper; ratio andill amounts proportional to the: demand being; made:upon--the boiler for s't'eam.-. At the: present-ti-mesthe amount oi ooal supplied to the firebox, either manually-or -v by a meohanical -stolger, is; controlled by the v fireman, whether; throughthefiremams neglect or to the} faet that; healsattending tgz other amounts proportional-to the"; demand Meafis or controlling} draftwifiiig p nvggitidnal locomotive.- nozzle;- or b eehanieal clfafting} to s'i'l bfply air; consistently amounts r b;tioha1' to the demand being made; upon the.- boiler tor steam have henetofoi e notr been; sueees'sful;

It is therefolfe aefurther object of my-invenltionto 'proyirie a combustion control system whereby coal from a mechanical-stokes and air from artu-rbine driven induced; draftfanr are supplied tothe firebox" int a substantially: constant prez-selected ration and whereby the coal and 7 air, in; 'suoh met-selected ratio; is supplied to the fixeb'ox in an amount proportional to; the demand upon; the: boiler for Swam andisautomatically varied in-accordance with suehdemandi Another object oi? the invention isto provide an automatic combustion: controL system for a mechanically drafted and mechanically: fired boiler"ofv the:foregoing type,for sequential operation -ofa the draftindueing-v-ian- 2mg; the-,sto'ger, whereby the draftindueing fan 'wil-l start first, foIlowed'l-by the stea in j ets that project, the eoal oVen;-the firebed',- and finally' i followed byoperation of the; coal conveying mechanism of the? stoke Anotheriob j eat; of," the-invention isf,to ;proyiile af'combustion' controlsystem ofth'etype despfibef d ionapplicationto a locomotive wherein-rtheash 2? panidampersaof the z-locoinotiye fireboiiare me; mati'cally; cl'oseda ulpon" cessationof operation; the draf-tvinducingtam-and; automfiia -y' P onoperation: of theidraiftinelucihg; fan; Addition-a1 objects; advantages nd-- r eii iI-IVBIltiOIl." reside in; the; construction arra-nge; ment and combinationotparts', as: be undelistood from the-preferred and praetieaLemboQif m'ent-ofq the invention: hereina-fter deseribed and illustratedinthe aocomganyingg drawings? 111 which a t.

Fig. 1 is a side elevation-of-theieatxtardlpox? tion; oi. alocomotive-,- with igortions o1f; the oath removed, showinggthee-invention applied thereto; Fig; 2;: is a reai genci eleiiation ;ofthelocoinotiyewith portions Off the eab' broken away; showing the in'ven-tion;applied thereto;; I M A Figs; 3 is a central -vertieal longitudinalseetion thrOug-h=;- the; forward end; of the locomotive, equipped inz accordance? with the: present invention some-partsbeinE;shown-in elevation; N

Fig. :47; is; ai fragmentary front eleyation; oi,- the lo'c'omotiveiireb'oxandash pan with the; ashqgan dampers and operating: mechanism therefor, shown applied thereto 5:. ifa hi f loeo n'etivejfirebgx and -ish .vi ewing it from the left side 'of Fi'g; 4;;w gtheashioari e and operatingmeehahis therefor, shown afiplid' e e ,7 1 i I F Q is a' s'tiohaliviwtalifi' ohtiinfiite-as zfi'i i-l; ,1 a. a i

Fig; '7 is'a sectional-iview-taken o'n theline-l-J shown the backhea dfof t head I3 h'as an op'eni through arranged; t' I t g opening and a stolge firnig'fofifiine a power operated" fire-door I 5; b eirig'laiiahgeili to, foi'iii ielosurefor the upper poi tionf of the firirig' oieii ing and azdibh lrge corikiuit [6 of estate; go ninuriioating with the lowerpbittioiilof. the fiiir ig opening;

t. .2 ease? smoke-b015- I was shown in Fig. 3. Steam delivered from the boiler to the dry pipe 20 fiows through the header 2| and is then delivered to a pair of steam pipes, one of which is shown at 22 in Fig. 3, which, as usual, lead to the inlet steam ports in the cylinder castings (not shown). Exhaust steam from the cylinders passes to atmosphere through the exhaust pipe 23 and exhaust stack 24 which projects through the compartment 25 of the smoke box l9.

Banks of inverted V-shaped angle irons forming a screen 26 separate the compartment 25 of the smoke box 19 from the" compartment 21 thereof. The screen 26 serves to separate cinders entrained in the combustion gases, and the cinders collecting at the bottom of the compartment 25 may be withdrawn and disposed of in any manner desired.

In a compartment 28 forward of the compartment 21, there is mounted a steam turbine 29 provided with a shaft 36 carrying a blower fan 31. The blower fan operates in the usual manner and sets up a draft which draws the products of combustion from the firebox 14 through the fines 18 into the smoke-box l9 and then into the circumferentially arranged flared tubular member 32 mounted on a wall 33 separating compartments 21 and 28, and registering with an opening 34 in the wall 33. All of the gases and products of combustion'must therefore pass through the fan 3| and will be-dis'charged therefrom into the compartment 28 from whence they escape through the stack 35. Live steam is admitted to the turbine 29 at 36 in 'the manner hereinafter described, and the l team, after passing through the turbine, is discharged through the outlet'31 into the compartment 28 and thence out through the stack 35.

Referring now to Figs. 1, 4 and 5, the numeral 38- designates the locomotive ash pan disposed beneath the firebox l4. The ash pan 38 is pro videdalong its opposite sides with the dampers 39' and 40 which control the air admission openings' between the mud ring (not shown) of the "firebox l4 and the-ash pan 38.

, The dampers 39 and 46 are L-shaped in cross 'fsection" and are mounted to swing as the longi- --tudinally'-extending rods 4| and 42, respectively,

are rotated. Referring specifically to Fig. 4, the dampers 39 and '40- are shown'in their open position, as indicated in full lines, while the dot and dash lines indicate-the position of the dampers 39 and 40 when they assume their closed position.

The rod 42 is rotatably mounted subjacent the outer side edge of the ash pan 38 in the looped end 43 of the bracket 44 as best seen in Fig. 6. A' plurality of such brackets is provided at spaced *intervals, as shown in Fig. 1 and a similar mounting arrangement is provided for the rod 41 which extends'longitudinally along the opposite side of the ash pan 38. Referring to Figs. 4 and 6, it will ibe seen that the brackets 44 are spaced from the under side of-th'e ash pan 38 subjacent the outer "side edges thereof by spacer members 45; and bolts 46 passing through the brackets 44, spacer members 45 and the ash pan 38, or other suitable means, may be employed to rigidly secure the brackets 44 to the ash pan 38.

The damper 49'is mounted to rotate with the rod 42 by means of a bracket 48 which is rigidly secured tothe damper in any suitable manner, as by welding, and which is provided at one end withadooped portion 49, as best seen in Fig. '1, that fits about and is rigidly secured to the rod 42 in any suitable manner, as by welding. A plurality of such brackets is provided at spaced in- 4 tervals, as shown in Fig. 1 and a similar mounting arrangement is provided for the damper 39 which extends longitudinally along the opposite side of the ash pan 38.

The dampers 39 and 40 are operated by a steam motor cylinder 59 which is mounted on a bracket 5| rigidly secured to and. depending from the mud ring (not shown) of the firebox. The cylinder piston 52 i connected by a link 53 with the lower end of a lever 54 which is secured intermediate its ends on the rod 42. Thus reciprocation of the piston (not shown) of the motor cylinder 59 will cause the rod 42 to alternately rotate first in one direction and then in the opposite direction, whereby the damper 40, which as previously explained is secured to :the rod 42, ismoved to its open or its closed position.

A rod 55 connects the upper end of the lever 54 with the lower end of the lever 56 which is rigidly secured intermediate its ends on the rod 4!, and since the damper 39 is mounted to rotate with the rod 4|, as previously explained, it will be seen that the dampers 39 and 46 act in unison. A tension spring 51' attached at one end to a rigid part of the locomotive and attached at its other end to the upper end of the lever 56, normally holds the dampers in closed position, as shown in dot and dash lines in Fig. 4. When steam is admitted to the motor cylinder 59, the dampers 39 and 49 are moved, through the operating connections above described, to their open position, as'shown in full lines in Fig. 4.

Referring now to Fig. 8, which is a diagrammatic representation of the control system, steam fOr operating the stoker engine 58, the fan turbine 29, the damper motor cylinder'50, and the steam emitted from the stoker distributor jet head 59 for projecting the coalinto the firebox, is supplied from the locomotive steam turret 68.

A steam line 6| leads from the steam turret to the stoker engine 58, supplying steam for operating the latter which in turn operates the stoker screw conveyor for advancing coal from the coal bin of the tender to the stoker distributor jet head 59 adjacent the firin opening of the locomotive firebox I4.

Interposed in the steam line BI is a diaphragm actuated valve 62 responsive we control system hereinafter described, for operating the stoker engine and consequently the stoker screw conveyor to deliver coal to the firebox in an amount proportional to'the demand being made upon the boiler for steam. I

A valve controlled by-pas's 63 is provided in the steam line 6| by-passing the diaphragm actuated valve 62 whereby the stoker engine 58, and consequently the stoker screw conveyor, may be operated independently of the control system.

A second steam line 64 leads from the steam turret 69 to the induced draft fan turbine 29, supplyin steam to the turbine for operatin the 'fan, which in turn effects an induced draft of air through the firebox to provide the necessary air tosupport combustion of the coal.

Interposed in the steam line 64 is a diaphragm actuated valve 65 responsive to the aforesaid control system, for operating the turbine 29 and "consequently the fan 3|, to provide an'induced seamenthe steam line 6 4 bypassing-the diaphragm ace tnated valve 65 whereby: the turbine 29; and

consequently the" induced draft fa-n"3-'l} maybe operated. independently" of the control system.

' steam line 6T- branches" ofithe stea m= line 614" at at point: between the diaphragm valve 65 and the; turbine 29' and communicates" with the damper" motor cylinder 50" for operating the dampers 39 and: Openingand' closing; of the dampers is thus also responsive to the controls-ystem and. sincethe admissionof steam to--- the damper cylinder" 50. and: cutting" of steam thereto. is; regulated by the same'valve. 65 that regulates a'dmissionof .steam t'o the fan turbine .29" and; cutting offiof; steamthereto; it" willbe seen that operation? of." the dampers is synchro.- nizedjwith operation ofthe induceddraft fan.

' A5, steam line.v 68 "leads" from-"the" steam turret? 60 to the stoker: distributor-- jet" manifold- 69; A" plurality of" steam supply pipes 'fll, preferahly five asshown in: Figure "8, lead from themanifold '69to individual chambers (not shown)" in the Stoker distributor'jet head59i Aswe'll knowniin the art, and therefore not shown, the front .face' of the" jet head is i provided with jet" openings communicating with; the" chambers of.v the jet head 59 the jet; openings being; so directed that the pressure: fluid jetstreams emittedtherefrom project'the' coal delivered by the toker screw conveyor overall'parts ofjthefirebox; A regulating valve such as amordihary globe, or needle valve. isplaced each supp.11 pipe. .10 j-between' the -.maniwljd d the distributor jet. head. 591' to. control the pressure oithejcoalprojecting steam blasts;

interposed inthe steam line, 'Gfliis a diaphragm actuated valve 12' responsive to the aforesaid control. system for permitting; flowof steam to.

the. manifold. 69 andjconsequently the distrib =utbr. jet. head' 59, and1fbr iiiterrupting the flow of steam thereto.

A. valve. controlled by-pass 13' is provided; in the. steam .line 68' by -passing the diaphragm actuated'valve, .72 wherebxsteam may 'besupplied tO.,tH8'. ma-nif(i1d 6.9', .andconsequently' to the; dis"- tiflziutoii jet head? '5 independently of the: con; tiolisystem. a The system for controlling the? operation of the. valves .62, 65, and '1;2is' operatedby air sup= plie'dfthrough thefliline fififlfrom'the' main reserr The controls consist; primarily off'three mstruments mounted on a panel ,,8I in" the left side of the backheadijliof "the prep-0x114; as best 158.; a .relay valve 86 which pcontrol'sthe operation of'the diaphragm va'lve 12"in the steam "11:15.63 leadinerto the stoker distribut rjet .m-anif' c1269": andja. relay valves} which .-.c n't1'.0ls the. 01381:-

anonofthe diaphragm valve iifiin the. steam line 64 leading to thedfamper 'motor cylinder? 50 For purpose of illustration; certain operating;

steam and air pressures will: be assumed in 1 the following description, it b'eingunderstood, how

ever; that these pressures" may be altered de pending on varying operati-ng conditions:

brought-from the mainreservoin (not shown);

of the locomotive through the air supply line: 30'. Ihterposedinthe line B0 is a 28 1b: per. sq; in iredhcingvalve 38% and an air filter1'89i The valve 99 in the by-pass line 9 1 Wh'ich-by' passes the: reducing valve 88 andair filter 89 is" normally closed, fwhile'valves 92 and 93 fore and aft of the amount of air 'pa'ssing through the'llne, W2

mally open.-

From the 28* lb'; per sq. in: side'roftheair supply line 8'5; air" is piped at that pressure to: relay? valves 8 BfiandTl tlirough the'branchlines-M 95 and 95?; respectively; to the steam pressure" controller 82 'throu'gh-braneh line 9l ;*to-the selector valve 83 'througl'i branchline 98; and to. the ratio controller 84 through branch line 99";

The steam-pressure controller 82 is equipped" with two hands, as shown in' 21a controlling hand 'l'fiil'; whichcan' be set tomaintain adesired pressure m the -boiler; e: g; 20.0 lbs: per-sq: inaf and' an indicating-hand Hil which shows we the-'- actual steampressurein the-boiler. Now; should the*-b'oi'ler-'pressure dropbelOw- -2001bs: per-sqa ini,

the-indicatonhand I 01 1? will lag: behind the controil'er hand ltliil; the steamz-pressurecontroller."

82*then' permits an'amount of'the 28 lb: per sq;

in; air supply; in proportionto the difference-- between the-indicated" and desired- 'boiler pres sure; topass through the-loading air line! 92 and" enterthe selector valve 83 as a loading pressure:

The-supply air entering the selector valve 83" through the branch supplyline 98"; thus leaves throughtheline I93 as al-controlled air pressure,

It is evident;- then, that' as'the indicatedboiler pressure drops furth'er and" furtherbelow the boiler: pressure" for? which. the controlling-hand Ian of the steam-pressure?" controller" 82' is" set;

increases; exerting a*greaterloading'pressure on the selector "valve 83'; which in turn causes. the selector valve'flfi toopen widertwhereby a greater amount of air passes from the branch supply 'l'ine'98tothe1line" I031 The airin the. line we becomes" controlled" loading air; the; pressure thereof-fluctuatingautomaticallyaszthedmand for steam on the boiler. increases 'or'decreases.

The controlledloadingpressure air line i 03 is branched; witlr-on'e branchline. IO lleadingto the ratio' controller" 84" 'and theother: branch line )5 leading to the relay'valve' 8 5T The" controlled air." loading pressure" in" the branch line. 1051' controls the operation of the.

relay valve tovarytheamount ofalr' passing from branch supply; line" 9.4 to. the-line I06. As the loadihgair pressure in line- IUE; increases, the relay valve 85 permits" a proportionatelygreateramount ofairto pass into the line" I03, and'ojfcourse viceversa; a lesseramount' ofaiif' as the loading air'pressure inline |B5"decrease s'.

Theamount of air passing throughline I06 and thence through branch line lflT'contrjols the extent" of theopening of. diaphragm valve 62} thereby controlling the flow" of steam throughline. 6'! to the stoker engine 58"'and consequent1ythe" speed? of its operati n and-2 the am unt of coal delivered to the firebox: l4' by, the stoker. 2

Air passing from the" line- I06" through the branch line I08 effects a loading pressure on the relay valve 86, controlling passage of supply air from branch supply line 95 to the line I09 which in turn effects the operation of diaphragm valve I2 in the steam supply line 68 to the distributor jet manifold 69. The valve I2 is arranged to open fully at a low pressure, e. g. '7 lbs. per sq. in., and since an appreciable amount of time must elapse before a sufdcient pressure is built up to operate the stoker engine 58, it is evident that the coal projecting steam blast from the distributor jet head 59 will come into operation before the stoker will operate. 9

Air from the 28 lb. per sq. in. branch supply line 99 enters the ratio controller 84 and leaves through the line IIO as a controlled loading air pressure for controlling the relay valve 81. The amount of air passing from the branch supply line 99 to the line is controlled by. a valve in the ratio controller, the setting of which is responsive to the controlled loading air pressure in the line I04. Thus the greater the loading air pressure in the line I04, in response to a greater demand for steam on the boiler, the more air will be admitted through the valve of the ratio controller 84 from the line 99 to the line H0.

The loading pressure of the air in the line H0 effects a loading pressure on the relay valve 81, controlling passage of supply air from branch supply line 96 to the line III which in turn effects the operation of the diaphragm valve 65 in the steam supply line 64 to the fan turbine 29. As the loading air pressure in line I [0 increases, the relay valve 81 permits a proportionately greater amount of air to pass into the line III, thereby opening the valve 65 a greater amount and admitting more steam to the fan turbine 29 to increase its speed. The speed of the turbine operated fan 3|. is thus responsive to demand for steam on the locomotive boiler.

The diaphragm valve 65 is set to open at a lower pressure than the diaphragm valve I2, e. g., at 3 lbs. per sq. in., so that it is apparent that the fan turbine 29 will operate before steam is admitted to the distributor jet head 59, and before the stoker becomes operative.

At. the same time that steam is admitted to the fan turbine 29 for operating the fan 3 I, steam is also admitted through branch line 61 to the damper cylinder 50 for opening the dampers 39 and 40. When the supply of steam to the fan turbine 29 is cut off, the supply to the damper cylinder 50 is also cut off, so that the dampers 39 and 40 close. Preferably a governor II2 driven off the stoker engine 58 is employed for governing the speed of the stoker engine. An oil pressure is set up in the oil line I I3 which opposes the pressure in the relay valve 85 of the loading pressure line I05. Thus if the stoker engine is operating at an ,excessive speed, the pressure in line H3 increases, and functions to restrict the amount of supply air passing through the relay valve 85, thereby partially closing the valve 62 and slowing up the speed of the stoker engine 58. It will be seen, therefore, that if a governor is employed, the amount of air which is allowed to pass through the relay valve 85 as an operating pressure on the diaphragm valve 62 is a function of the differential in pressure between the loading pressure line I05 and oil pressure line II3.

Means governing the speed of the fan turbine 29 is preferably also provided. This includes a pipe II4 leading from the combustion chamber of the firebox I4 to the ratio controller 84,

8 and a pipeII5 leading from the smoke box, I9 to the ratio controller 84. As the speed of the fan 3| increases a differential in pressure is set up between the combustion chamber and the smoke box which is communicated to the ratio controller 84 by means of the pipesI I4 and H5, where this differential pressure is arranged to oppose the loading pressure from line I04, there-' by limiting the amount of supply air passing from the branch supply line 99 to the line H0, which in turn functions to restrict the amount of supply air passing through the relay valve 81 thereby partially closing the diaphragm valve 65 and slowing up the speed of the fan turbine 29.

Preferably a lag device is interposed in the line III which leads to the diaphragm valve 65, to permit the fan 3 I to operate for a short time after steam to the distributor jet head 59 has been cut off and the stoker engine has stopped. This ine cludes a by-pass line I IS in the line i I I, by-p'assing a check valve III, with a needle valve H0 in the by-pass line I I6. The check valve In permits air to pass to the diaphragm valve 65', but cuts off return of air, so that the air must pass through the needle valve IIB of the by-pass line H5. Thus while the valve 65 can open quickly, closing thereof is delayed. From the above description it is apparent that the operation of the stoker, the distributor jets, the draft fan, and the dampers is automatically controlled in accordance with demand for steam on the boiler. l

Shifting from automatic control to manual control is accomplished through the selector valve 83, which can be manipulated to cut off the load; ing pressure from line I02 and can be manually operated to effect a desired loading pressure, thereby controlling the amount cf'air passing from the air supply branch line sfithrough the selector valve to the controlled loading pressure line I03. The rest of the control system will of course function as'before.

The ratio controller 84 is provided withmanu: ally operated means whereby the ratio of fair to coal may be changed. Optimum combustion conditions vary for different kinds of coal, some requiring more air than others, and by properly setting the ratio controller, the desired ratio of air to coal may be delivered.

The various instruments employedin the control system, the steam-pressure controller 'B2, selector valve 83, ratio controller 84 and relay valves 85, 86, 81, are well known in the art, and the details of construction are therefore not shown in the drawings or described.

From the description of the system, set forth in detail above, it is apparent that the amount of air induced by the fan as draft through the firebox and the amount of coal delivered by the stoker are proportional to the demand being made upon the boiler for steam, the amount of coal and air in pre-selected ratio, being increased or decreased automatically as the demand on the boiler increases or decreases.

Other features include the automatic operation of the coal distributing jets when there is a sufficient demand for steam to cause functioning of the stoker engine and the draft fan and the automatic cutting off of the coal distributing jets when the demand for steam is satisfied and operation of the stoker engine and draft fan ceases.

Ash pan dampers of the locomotive automatically open when the draft fan starts to operate and: :a utomatically close whenf'the draft i-fan stops. I

Automatic sequential operation of the draft fan, the coal distributing jets and the stoker, in

that order, is 'provided'j'wherebysmoke is kept ,at' a-minimum.

While the invention has been described with reference to the specific embodiment disclosed and with reference to'specific'operatin pressures, it will be obvious that changes may be'm'ad'e Without departing from thespirit and scope of tlielinvention. "I claim:

Tl. A combustion control 's'ystem for'use in-a mechanically firedand draftedsteam locomotive provided 'witha stokerfuel conveyor, a stoker fuel distributor and a draft producing blower, said system comprising air pressure loading means responsive to varying demands-on the locomotive boiler for -steam for effecting corresponding proprovided with a stoker engine, a stoker distributor jet head and an induced draft fan turbine, said system comprising air pressure loading means responsive to varying demands on the locomotive boiler for steam for effecting corresponding proportionate varying loading air pressures, pressure sensitive valves in throttling relation to the steam supply of the stoker engine and fan turbine, said valves being responsive to said varying loading air pressures for correspondingly varying the speed of the stoker engine and fan turbine, and a pressure sensitive valve associated with the steam supply of the stoker distributor jet head, said last named valve being responsive to said varying loading air pressures for admitting steam to the stoker distributor jet head, said pressure sensitive valves having different actuating sensitivity for initial sequential functioning of the fan turbine, stoker distributor jet head and stoker engine, in that order.

3. A combustion control system for use in a mechanically fired and drafted steam locomotive provided with a stoker engine, a stoker distributor jet head, an induced draft fan turbine and an ash pan air damper operating motor cylinder, said system comprising air pressure loading means responsive to varying demands on the locomotive boiler for steam for effecting corresponding proportionate varying loading air pressures, supply lines for supplying steam to said stoker engine, distributor jet head, fan turbine and damper operating motor cylinder, pressure sensitive valves in throttling relation to the steam supply of the stoker engine and fan turbine, said valves being responsive to said varying loading air pressures for correspondingly varying the speed of the stoker engine and fan turbine, a connection from the steam supply of the turbine fan to the damper cylinder for controlling the position of the damper, and a pressure sensitive valve associated with the steam supply of the stoker distributor jet head, said last named valve being responsive' to said varying loading air pressures 4. A combustion control system for-use in ;.a

steam locomotiveprovi'ded with a pressure 'fluid operated stoker engine for driving 'the stoker coal conveying means, a pressure fluid blast emitting stoker distributor jet head for project"- inglthe conveyed coal 'into the locomotive firebox,

and apre'ssure fluid turbine driven fanfor irrducing draft through the firebox, said system comprising supply lines for delivering pressure fluid "to the stoker engine, the stoker distributor jetheadiandthe fan turbine, a pressure sensitive valve -in"each of saidsupply lines responsive-to variations in pressure imposed .thereon, .an air pressure line communicating with "each of said "pressurersensitive valves, and airipressurez-load ingide'vicesassoci'ate d'swith said air .ipressure lines responsive to variations'in the boiler .pr'essurenf the locomotive for correspondingly varying :the

-'-air:pressure imposed oni'sai'ditpressure sensitive valves to control the passage of pressure fluid to said stoker engine, stoker distributor jet head and fan turbine, the pressure sensitive valve controlling functioning of the stoker distributor jet head being set to open fully at a pressure below the operating pressure of the stoker engine, and the pressure sensitive valve controlling functioning of the fan turbine being set to open ata pressure below the openin pressure of the pressure sensitive valve controlling functioning of the stoker distributor .jet head, for sequential functioning of the fan turbine, stoker distributor jet head and stoker engine, in that order.

5. A combustion control system for use in a steam locomotive provided with a pressure fluid operated stoker engine for driving the stoker coal conveying means, a pressure fluid blast emitting stoker distributor jet head for projecting the conveyed coal into the locomotive firebox, and a pressure fluid turbine driven fan for inducing draft through the firebox, said system comprising supplylines for delivering pressure fluid to the stoker engine, the stoker distributor jet head and the fan turbine, a pressure sensitive valve in each of said supply lines responsive to variations in pressure imposed thereon for controlling passage of pressure fluid to said stoker engine, stoker distributor jet head and 7 fan turbine, an air pressure supply line communicating with each of said pressure sensitive valves, air pressure loaded valves controlling the passage of air through said last named supply lines to said pressure sensitive valves, and means associated with an air pressure supply line responsive to variations in the demand on the 10- comotive boiler for steam, for proportionately controlling the loading air pressure on said air pressure loaded valves, and means responsive to the pressure differential between the smoke box and firebox of the locomotive for effecting operated stoker engine for driving the stoker I coal conveying means, a pressure fluid blast emitting stoker distributor jet head for projecting the conveyed coal into the locomotive flrebox, and a pressure fluid turbine driven fan for inducingdraft through the firebox, said system comprising supply lines for delivering pressure fluid tothe stoker engine, the stoker distributor jet head and the fan turbine, a pressure sensitive valve in each of said supply lines responsive to variations in pressure imposed thereon for controlling passage of pressure fluid to said stoker engine, stoker distributor jet head and fan turbine, an air pressure supply line communicating with each of said pressure sensitive valves, air pressure loaded valves controlling the passage of air through said last named supply lines to said pressure sensitive valves, and means associated with an air pressure supply line responsive to variations in the demand on the locomotive boiler for steam, for proportionately controlling the loading air pressure on said air, pressure loaded valvesy'and means responsive-to the speed of the stoker engine for effecting a, loading pressure opposing the loading pressure of the air pressure'loaded valve associated with the stoker engine controlling pressure sensitive valve, whereby to impose a governing control on the speed oI-"the stoker engine.

FRED D. MOSHER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,388,030 Down et a1. Aug. 16, 1921 1,656,486 Huntington et al. Jan. 1'7, 1928 2,141,082 Dickey Dec. 20, 1938 2,212,125 Peebles Aug. 20, 1940 2,259,417 Gorrie Oct. 14, 1941 2,328,499 Saathofi' Aug. 31, 1943 FOREIGN PATENTS Number Country Date Great Britain May 20, 1931 

